Question

我正在使用OpenResty Nginx，并在Nginx conf中有一段Lua脚本。（下面的样本，但为简洁而截断）。这在nginx.conf文件中正常工作。

rewrite_by_lua '

    -- Load Memcached module
    local memcached = require "resty.memcached"
    local memc, err = memcached:new()
    if not memc then
        ngx.log(ngx.ERR, "Failed to instantiate memc: ", err)
        return
    end
'

但是，如果我将此脚本解压缩到文件memcached.lua然后将其包含在带有rewrite_by_lua_file的nginx配置中，我将无法重新启动nginx并收到有关语法错误的通知，例如：

unexpected "," in /etc/nginx/sites-enabled/memcached.lua

unknown directive "--" in /etc/nginx/sites-enabled/memcached.lua

如果我完全删除了ngx.log行，语法错误就会消失。

为什么语法在nginx conf中有效，但是当我将其提取到单独的文件时却没有？我在某处读过字节码，但不确定这是否相关？

修改

这是.lua文件的完整输出。如果它通过rewrite_by_lua

直接嵌入到nginx.conf文件中，则此确切代码有效

cat /etc/nginx/sites-enabled/memcached.lua

-- Define Memcached key
local memcached_key = "saas_" .. ngx.var.host

-- Load Memcached module
local memcached = require "resty.memcached"
local memc, err = memcached:new()
if not memc then
    ngx.log(ngx.ERR, "Failed to instantiate memc: ")
end

-- Set Memcached timeout
memc:set_timeout(1000)

-- Connect to Memcached daemon
local ok, err = memc:connect("127.0.0.1", 11211)
if not ok then
    ngx.log(ngx.ALERT, "Failed to connect to Memcached: ", err)
end

-- Query for branch name in Memcached
local branch, flags, err = memc:get(memcached_key)
if err then
    ngx.log(ngx.NOTICE, "Failed to get account from Memcached: ", err)
end

-- If branch not found in Memcached, ask MySQL instead
if not branch then

    -- Load MySQL module
    local mysql = require "resty.mysql"
    local db, err = mysql:new()
    if not db then
        ngx.log(ngx.ALERT, "Failed to instantiate MySQL: ", err)
        return
    end

    -- Set MySQL timeout
    db:set_timeout(1000) -- 1 sec

    -- Connect to MySQL daemon
    local ok, err, errno, sqlstate = db:connect{
        path = "/var/run/mysqld/mysqld.sock",
        database = "dbname",
        user = "dbuser",
        password = "dbpass" }
    if not ok then
        ngx.log(ngx.ALERT, "Failed to connect to DB: ", err, ": ", errno, " ", sqlstate)
        return
    end

    -- Define subdomain string by extracting it from the http hostname
    local subdomain = string.match(ngx.var.host, "([%w-]+).")
    local quoted_subdomain = ngx.quote_sql_str(subdomain)

    -- Execute an SQL query to get the branch name based on the subdomain
    local sql = "SELECT branch FROM saas_account WHERE account = " .. quoted_subdomain
    local res, err, errno, sqlstate = db:query(sql, 1)
    if not res then
        ngx.log(ngx.ALERT, "Bad result from DB: ", err, ": ", errno, ": ", sqlstate, ".")
        return
    end

    -- Check we got a result
    if not res[1] then
        ngx.log(ngx.NOTICE, "No docroot was returned for subdomain: ", subdomain)
        ngx.var.branch = "chaletops"
    -- Assign the result from MySQL to the Nginx variable
    else
        ngx.var.branch = res[1].branch

        -- Store the result from MySQL back in to Memcached with a lifetime of 1 hour (3600 seconds)
        local ok, err = memc:set(memcached_key, ngx.var.branch, 3600)
        if not ok then
            ngx.log(ngx.WARN, "Failed to set branch in Memcached: ", err)
            -- return
        end
    end

    -- Save MySQL KeepAlive connection
    local ok, err = db:set_keepalive(10000, 100)
    if not ok then
        ngx.log(ngx.ALERT, "Cannot set MySQL keepalive: ", err)
        return
    end

    ngx.log(ngx.NOTICE, "Loading branch from MySQL: ", ngx.var.branch)

-- Else we did get a result from Memcached
else

    -- Assign the result from Memcached to the Nginx variable
    ngx.var.branch = branch

    ngx.log(ngx.NOTICE, "Loading branch from Memcached: ", ngx.var.branch)

end

-- Save Memcached KeepAlive connection
local ok, err = memc:set_keepalive(10000, 100)
if not ok then
    ngx.log(ngx.ALERT, "Cannot set Memcached keepalive: ", err)
    -- return
end

解

TL：DR - 将.lua文件放在Nginx配置目录之外。

在被要求发布确切的错误消息后，我不得不重新创建问题。对于参考和Google搜索者，错误消息如下：

2015/12/17 10:04:02 [emerg] 6903#0: unexpected "," in /etc/nginx/sites-enabled/memcached.lua:18

这次我从我的nginx.conf中复制了Lua代码并将其放在一个名为memcached.lua的文件中，并将其保存在我的项目目录中。然后我将以下include添加到我的nginx.conf中代替Lua脚本：

rewrite_by_lua_file /path/to/my/project/memcached.lua;

立即开始工作！

以前我通过将它从我的项目目录中的符号链接到/etc/nginx/sites-enabled/memcached.lua来包含它（假设它实际上与包含它的.conf一起生活更好）然后只使用了rewrite_by_lua_file memcached.lua;因为它是相对的.conf文件。

所以我最初想知道是不是因为rewrite_by_lua_file函数不能遵循符号链接或其他东西，但后来我突然意识到它与Lua include语句无关，但显然（现在！）因为符号链接在/etc/nginx/sites-enabled中，因此Nginx自动尝试加载文件，就好像它是一个普通的Nginx配置文件一样。

这是因为Nginx（在Ubuntu / Linux Mint上）配置为使用路径/etc/nginx/sites-enabled/*导入所有配置文件到它的主配置。

我认为我犯这个简单错误的原因是，在更高版本的Ubuntu上使用Apache时，会发生类似的过程，但是对于Apache（我更习惯），你有一个/etc/nginx/sites-enabled/*.conf的包含路径 - 即它特别需要.conf文件扩展名，这就是我错误地认为Nginx不会尝试包含我的.lua文件的原因。

OpenResty rewrite_by_lua与rewrite_by_lua_file - 语法错误

修改

解

0 个答案: